Error Management; Table 5-1 Description Of The Error Types - Fujitsu FR Family FR60 Lite User Manual

5.2.3

Error management

CAN error management is defined in its protocol. Five types of error detection and three types of status
are used.
1. Error detection
As shown in "Table 5-1 Description of the error types", errors that can be detected depends on
whether the node is transmitting or receiving.
Error type
Bit error
ACK error
Stuff error
CRC error
Format error
2. Statuses
Each node has error counters whose value depends on the status. The error counters of the nodes
are named TEC (transmit error count) and REC (receive error count) intending transmission and
reception. The three statuses are as described below.
Status
Error active
Error passive
Bus off

Table 5-1 Description of the error types

Transmitting Receiving
node node
○
-
○
-
○
-
○
-
○
-
The node is normally joining in the bus.
The node has frequent errors so it is influencing the bus.
The node is disconnected from the bus. To restore to the bus, the bus needs to
satisfy the restoration condition.
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AN07-00180-3E
Description
Detected if there is a difference between the
transmitted data and the bus level.
Detected if an acknowledgement
transmission cannot be obtained.
Detected if bit stuffing is not applied. Bit
stuffing is to set an inverted bit by 5 bits if
the number of successive bits with the same
level is 5 or more. This prevents bits with the
same level from being successive over 6 bits.
Detected if CRC (cyclic redundancy check)
fails on the received data.
Detected if the received data does not
confirm to any of the frame formats.
Description
to